Evaluating the Correlation between Serum Prostate-specific antigen Values and Gleason Score of the Prostate Carcinoma with Gallium 68- Prostate-specific membrane antigen Uptake in the Prostate Tumor in Primary Staging

Abstract

Abstract Objective Gallium-68 - prostate-specific membrane antigen (Ga68-PSMA) PET/CT plays a crucial role in staging, evaluating treatment, and diagnosing local recurrence of prostate tumors. The National Comprehensive Cancer Network ( NCCN) guidelines have recently recommended it as the preferred staging method for unfavorable intermediate and high-risk patients. This study aims to evaluate the correlation between serum prostate-specific antigen (PSA) levels and the Gleason score of prostate tumors with the findings of Ga 68-PSMA PET/CT scans in primary staging. Methods In this cross-sectional study, newly diagnosed prostate cancer patients referred for Ga68-PSMA PET/CT whole-body scans were enrolled. The scans were performed at three-time points (early, whole-body, and late). The standardized uptake value of Ga68-PSMA in the primary tumor and its association with serum PSA levels, tumor Gleason score, and presence of tumor metastasis were evaluated and analyzed. Results Forty-nine male patients, 65 years old on average (interquartile range (IQR): 59–69) were included in the study. Of these patients, 43.9% were classified as high-risk based on their Gleason score (8–10). The median serum PSA level was 17 ng/mL (IQR: 8.02–42.10). PSA levels correlated with the maximum standardized uptake value (SUVmax) of the tumor in the whole-body stage of the scan (p < 0.05; r = + 0.392) but not in the early or late stages (p > 0.05). Gleason scores positively correlated with tumor SUVmax in all three scan stages (p < 0.05). Conclusions Our results indicate that the Gleason score significantly correlates with the SUVmax of the prostate tumor in all three-time points of the scan. However, serum PSA levels only correlate with the tumor SUVmax in the whole-body stage of the scan, not in the early and late stages. In the whole-body stage, a higher SUVmax is significantly associated with higher Gleason scores, bladder wall, invasion of the seminal vesicle, and lymph node metastasis (p < 0.05).